This invention relates to a process for catalytically hydrogenating unsaturated fatty acids and more particularly to accomplishing this in rapid fashion under reasonably mild hydrogenation conditions.
Unsaturated fatty acids are refractory towards hydrogenation and typically require extreme high temperature, extreme high pressure, protracted hydrogenation time or combinations thereof in order to satisfactorily hydrogenate them. Conventionally, unsaturated fatty acids are hydrogenated with hydrogen gas in the presence of at least 0.2 to 0.5% nickel hydrogenation catalyst and usually more at temperatures in excess of 150.degree. C. under pressures of at least 200 to 300 psig and more often 600 to 1000 psig and higher. Times of at least 6 to 8 hours or more normally are required in order to satisfactorily hydrogenate the fatty acids. By contrast, hydrogenation of glyceride oils (which generally are not refractory towards hydrogenation) typically can be accomplished in relatively short times at about 100.degree. to 260.degree. C. at pressures of around 0 to 100 psig. Fatty acids, then, are adjudged to be refractory towards hydrogenation by comparison and contrast to glyceride oils. Hydrogenation of fatty acids and glyceride oils is outlined in Bailey's Industrial Oil and Fatty Products, 3 rd Edition, Pages 719-896 (Interscience Publishers, New York, New York, 1964), the same being expressly incorporated herein by reference.